This month, in Minnesota’s deep snow and crisp December air, we put 45Nrth’s most anticipated new product to the test, a winter riding boot dubbed the Wölvhammer.

The Wölvhammer in its element on Minneapolis’ Greenway bike path

The ‘Hammers, as our office has taken to calling them, were shipped to dealers across the country late last week, and they’ve been showing up on bike shop shelves the past few days.

By early accounts, the $325 boots haven’t had much chance to gather dust, as cold-weather cyclists have been snatching them up like über-thermal hotcakes, according to our industry sources.

In my test so far, the Wölvhammers have proven to be two things: Warm and heavy.

Both of these traits make sense considering the design inspiration: “We started by taking what works well in mountaineering boots and made a cycling shoe — rather than taking a cycling shoe and trying to make it warm,” said David Gabrys, 45Nrth brand manager.

Waterproof Cordura outer and rugged Vibram sole

The “mountaineering boot” approach is what sets the Hammers apart from other cold-weather cycling boots we’ve ridden, including the Lake MXZ302, which has been a go-to boot for the coldest riding conditions.

The Wölvhammer is different from the Lake in its build — it’s a fully-functional boot that just happens to have room for a cycling cleat on the bottom. The Vibram sole could be slapped on a climbing boot. The Cordura outer is waterproof and extra tough.

Gabrys noted that the Wölvhammer is produced in the same factory where snowboarding boots and Scandinavian motorcycle boots are made. This is apparent when you pull them on — the boots are stiff, solid, stuffed with 200 grams of Thinsulate insulation and finished off with an Aerogel insert that blocks cold that might otherwise seep in from the cleats.

Not surprisingly, the Wölvhammers are the warmest cycling boots we’ve ever ridden with. We’ll see how low they can go as the winter rolls on, but they’ve already proven easily capable of handling temperatures in the low teens (F) for well over an hour. And by “easily capable,” I mean my feet feel like they’ve gone south for the winter, while the rest of my body is stuck in Minnesota on a frigid December day.

As noted, the luxurious warmth doesn’t come for free. In addition to the heavy $325 price tag, there’s definitely a price to pay when it comes to the weight of these boots, too. The Wölvhammer tips our scale at 770 grams each (Euro size 44), which is a good 200 grams or more than most other winter-cycling shoes we own.

In my mind, there’s a difference between heavy and clunky. And while these boots are definitely heavy, they don’t feel clunky or clumsy on the bike or walking around.

In short, they’re big, but they’re efficient — each component of the boot, from the high cuffs to the super-burly outsole and Aerogel inserts are key to making the boot as warm as it is. And my oft-cold toes appreciate it!

Keeping in mind that most winter cyclists don’t have to suffer through the extreme cold of Minnesota winters, the Wölvhammer is overbuilt for many types of winter riding and many winter climates. If “winter” in your town is 40 degrees and rain, then go with shoe covers alone and save your cash.

Beyond commuting or training rides, a boot like the Wölvhammer is the ideal for riders in endurance races. This includes races like the Arrowhead 135 and dozens of other on-snow, long distance bike races held around the continent each year.

Off the bike, the sole grips snow and can kick steps into a slope. They’re comfortable enough to hike, if needed, pushing a bike for miles along an icy expanse. Gaiters also fit on ‘em.

Stepping back from those extremes, for me thus far the boots have been everything I need to get through a frigid Minnesota day. Rather than losing feeling in my toes, I’m now free to enjoy my burning quads and frozen eyelashes. Indeed, the day the Wölvhammer boots no longer cut it during a ride here will be the day I finally move somewhere warmer. And I don’t anticipate that happening anytime soon.